Ionic liquids directed syntheses of water-stable Eu- …Ionic liquids directed syntheses of...
Transcript of Ionic liquids directed syntheses of water-stable Eu- …Ionic liquids directed syntheses of...
Ionic liquids directed syntheses of water-stable Eu- and
Tb-organic-frameworks for aqueous-phase detection of nitroaromatic
explosives
Jian-Hua Qin,a,b
Bing Ma,a Xiao-Fei Liu,
a Hong-Lin Lu,
a Xi-Yan Dong,
a Shuang-Quan Zang*
a and
Hongwei Hou*a
a College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China.
b College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022, China.
Author for correspondence:
Prof. S.-Q. Zang, E-mail: [email protected];
Prof. H.-W. Hou, E-mail: [email protected].
Electronic Supplementary Material (ESI) for Dalton Transactions.This journal is © The Royal Society of Chemistry 2015
Supporting Information
Fig. S1 Supporting structure figure.
Fig. S2 Thermogravimetric curves of 1 and 2.
Fig. S3-S4 Excited state calculation.
Fig. S5 Solid-state excitation and emission spectra for H3BTB.
Fig. S6-S7 The fluorescence decay curves for 1 and 2.
Fig. S8-S20 Details of detecting of nitroaromatic explosives in the aqueous phase.
Fig. S21-S22 The band like diffuse reflectance spectra of solid samples of 1 and 2.
Fig. S23 The absorption spectrum of the selected analytes in water.
Table S1. Crystallographic data and structure refinement details for 1 and 2.
Table S2. Selected bond lengths (Å) and angles (°) for 1 and 2.
Table S3. Saturated vapor pressure for each of the analytes at room temperature (25 °C).
Table S4. Approximate sizes of selected analytes.
Table S5. HOMO and LUMO energies calculated for H3BTB and nitroaromatic explosives at
B3LYP/6-31G** level of theory.
Fig. S1 Schematic representation of the 6-connected (44.6
7.8
4)(4
8.6
7) topology (orange nodes for BTB ligands and
cyan nodes for Eu(III) centers).
Fig. S2 Thermogravimetric curves of 1 and 2.
Excited state calculation
The molecular geometry of free ligand H3 BTB was optimized using density functional theory (DFT) at the
B3LYP/6-31G* level, as shown in Fig. S3. Based on the optimized geometry, the energy of the lowest triplet
excited state of H3BTB was calculated to be 2.9044 eV (23426 cm-1
) using the time-dependent DFT approach. All
the calculations were performed in Gaussian03 software. Using the same approach, the molecular geometry of
ligand BTB coordinating with Ln3+
ions was also analyzed (Fig. S4), and the energy of the lowest triplet excited
state of BTB was calculated to be 2.9551 eV (23835 cm-1).
Fig. S3 The optimized geometry of free ligand H3 BTB at the B3LYP/6-31G* level.
Fig. S4 The optimized geometry of ligand BTB in MOFs at the B3LYP/6-31G* level.
Fluorescent properties
The excitation spectra of 1 and 2 are monitored around the more intense Ln3+
emission lines, 610 nm for
Eu(III) and 541 nm for Tb(III). It can be seen clearly that the excitation spectrum of 1 consists of a broadband and
a weak line. The broadband below 350 nm is due to the charge-transfer between the O2−
and Eu(III) ions and π →
π* electron transition of the organic bridging ligands. The excitation spectrum of 2 displays a large broadband
with a structured profile in the UV spectral region which is ascribed to the electronic transitions of organic ligands.
The absolute high intensity of the broadband compared to that of the intra4fn lines indicates that the π → π*
electron transition of the organic bridging ligands is a dominant path to sensitizing Eu(III)/Tb(III) excited states.
Complexes 1 and 2 emit red and green fluorescence, respectively. As is well known, the 5D0 →
7F2 transition
of Eu(III) is hypersensitive to site symmetry and of the electric-dipole (ED) nature, while the 5D0 →
7F1 transition
is insensitive to site symmetry and the magnetic-dipole (MD) nature according to Judd-Ofelt theory. Besides, the
5D0 →
7F0 transition of Eu(III) is invisible in the emission spectrum, which is only allowed for Cs, Cn, and Cnv
site symmetries according to the ED selection rule. These experimental facts thus suggest that the Eu(III) ion in 1
is located at a high-symmetry site, which is in good agreement with our single-crystal X-ray analysis. For 2, the
dominant band of these emissions is attributed to the hypersensitive transition 5D4 →
7F5 of Tb(III) ions, while the
stronger luminescent band corresponds to 5D4 →
7F6 transition, and the two less intense bands are ascribed to
5D4
→ 7F4 and
5D4 →
7F3 transitions, respectively. The
5D4 → 7
FJ (J = 2−0) transitions are measured with weak
intensity. It is worth noting that there is no apparent residual ligand-based emission in the 400−450 nm region,
indicating the energy transfer from the ligand to the lanthanide center is very effective and can sensitize the
lanthanide emission to a large extent.
The emission quantum yields were measured at room temperature under the excitation wavelengths that
maximize the emissions of lanthanide cations. As a result, the quantum yields are 19.2% for 1 and 0.6% for 2. The
fluorescence decay curves of 1 and 2 were also obtained at room temperature (Fig. S6 and S7). The corresponding
lifetime for 1 is about τ1 = 0.53 (100%) ms, and that for 2 is about τ1 = 0.22 (86.86%) ms and τ2 = 0.98 (13.14%)
ms (determined by monitoring 5D0 →
7F2 line for 1 and
5D4 →
7F5 line for 2 excited at 350nm). Complexes 1 and
2 both have a relatively long quantum yield and a fluorescence lifetime. Because the excitations now fall in the
range of those commercially available, they could be good candidates for light-emitting diodes (LEDs) and light
applications.
Fig. S5 Solid-state emission spectra for H3 BTB at room temperature.
Fig. S6 The fluorescence decay curve for 1.
Fig. S7 The fluorescence decay curve for 2.
(a) (b)
Fig. S8 The emission spectra (a) and the fluorescent intensity (b) for 1 dispersed in H2O, MeCN, DMF, BZ, TO,
BrBZ, PX, and 1 mM or saturated aqueous solutions of eight different analytes at room temperature.
(a) (b)
Fig. S9 (a) Fluorescence titration of 1 dispersed in aqueous solution by gradual addition of NB.
(b) Stern-Volmer plot of F0/F vs. NB concentration in aqueous solution for 1.
(a) (b)
Fig. S10 (a) Fluorescence titration of 1 dispersed in aqueous solution by gradual addition of 2-NT.
(b) Stern-Volmer plot of F0/F vs. 2-NT concentration in aqueous solution for 1.
(a) (b)
Fig. S11 (a) Fluorescence titration of 1 dispersed in aqueous solution by gradual addition of TNP.
(b) Stern-Volmer plot of F0/F vs. TNP concentration in aqueous solution for 1.
(a) (b)
(c) (d)
(e)
Fig. S12 Fluorescence titration of 1 dispersed in aqueous solution by gradual addition of saturated aqueous
solutions of 1,3-DNB (a), 1,4-DNB (b), 2,4-DNT (c), 2,6-DNT (d), and TNT(e)
Fig. S13 The emission spectra for 2 dispersed in H2O and 1 mM or saturated aqueous solutions of the selected
analytes at room temperature.
Fig. S14 Quenching efficiency of the fluorescent intensity for 2 dispersed in 1 mM or saturated aqueous solutions
of the selected analytes at room temperature. (excited and monitored at 300 nm and 541 nm, respectively).
(a) (b)
Fig. S15 The emission spectra (a) and the fluorescent intensity (b) for 2 dispersed in H2O, MeCN, DMF, BZ, TO,
BrBZ, PX, and 1 mM or saturated aqueous solutions of eight different analytes at room temperature.
(a) (b)
Fig. S16 (a) Fluorescence titration of 2 dispersed in aqueous solution by gradual addition of NB.
(b) Stern-Volmer plot of F0/F vs. NB concentration in aqueous solution for 2.
(a) (b)
Fig. S17 (a) Fluorescence titration of 2 dispersed in aqueous solution by gradual addition of 2-NT.
(b) Stern-Volmer plot of F0/F vs. 2-NT concentration in aqueous solution for 2.
(a) (b)
Fig. S18 (a) Fluorescence titration of 2 dispersed in aqueous solution by gradual addition of TNP.
(b) Stern-Volmer plot of F0/F vs. TNP concentration in aqueous solution for 2.
(a) (b)
(c) (d)
(e)
Fig. S19 Fluorescence titration of 2 dispersed in aqueous solution by gradual addition of saturated aqueous
solutions of 1,3-DNB (a), 1,4-DNB (b), 2,4-DNT (c), 2,6-DNT (d), and TNT(e)
Fig. S20 Quenching efficiency of 2 dispersed in aqueous solutions at different concentrations of
NB, 2-NT, and TNP.
Fig. S21 The band like diffuse reflectance spectrum of a solid sample of 1.
The optical band gap is estimated to be ~2.7 eV.
Fig. S22 The band like diffuse reflectance spectrum of a solid sample of 2.
The optical band gap is estimated to be ~3.2 eV.
Fig. S23 The absorption spectrum of the selected analytes in water.
Table S1. Crystallographic data and experimental details for 1 and 2.
R= [ F0 –Fc/ F0 ], RW =W [F02 –Fc
2
2/ W (Fw
2) 2]1/2
Complex 1 2
Formula C27H17EuO7 C27H17TbO7
Formula weight 605.37 612.33
Crystal system Orthorhombic Orthorhombic
Space group Fddd Fddd
a (Å) 22.543(5) 22.482(5)
b (Å) 29.134(6) 28.996(6)
c (Å) 29.168(6) 29.067(6)
V (Å3) 19157(7) 18949(7)
Z 32 32
Dc (g/cm3) 1.679 1.717
Abs coeff/mm–1 2.664 3.031
F(000) 9536 9600
θ range for data collection (°) 2.68/25.50 2.69/25.50
Data/restraints/parameters 4365/53/316 4326/84/316
GOF 1.253 1.085
R [I > 2σ(I)] R1 = 0.0727
wR2 = 0.1546
R1 = 0.0789
wR2 = 0.2922
R (all data) R1 = 0.0755
wR2 = 0.1564
R1 = 0.0860
wR2 = 0.3034
Table S2. Selected bond lengths (Å) and angles (°) for 1 and 2
Complex 1
Eu(1)-O(4)#1 2.300(7) Eu(1)-O(2)#5 2.391(6)
Eu(1)-O(5)#2 2.331(8) Eu(1)-O(1) 2.397(6)
Eu(1)-O(6)#3 2.333(7) Eu(1)-O(7) 2.505(6)
Eu(1)-O(3)#4 2.338(7) Eu(1)-O(2) 2.809(8)
O(4)#1-Eu(1)-O(5)#2 120.5(3) O(2)#5-Eu(1)-O(1) 125.6(3)
O(4)#1-Eu(1)-O(6)#3 87.0(3) O(4)#1-Eu(1)-O(7) 76.4(3)
O(5)#2-Eu(1)-O(6)#3 132.7(3) O(5)#2-Eu(1)-O(7) 143.7(4)
O(4)#1-Eu(1)-O(3)#4 82.4(3) O(6)#3-Eu(1)-O(7) 75.5(4)
O(5)#2-Eu(1)-O(3)#4 76.6(3) O(3)#4-Eu(1)-O(7) 74.2(4)
O(6)#3-Eu(1)-O(3)#4 149.4(3) O(2)#5-Eu(1)-O(7) 144.2(4)
O(4)#1-Eu(1)-O(2)#5 79.0(3) O(1)-Eu(1)-O(7) 75.8(3)
O(5)#2-Eu(1)-O(2)#5 71.9(3) O(4)#1-Eu(1)-O(2) 147.0(2)
O(6)#3-Eu(1)-O(2)#5 77.6(3) O(5)#2-Eu(1)-O(2) 72.0(3)
O(3)#4-Eu(1)-O(2)#5 127.6(3) O(6)#3-Eu(1)-O(2) 66.3(3)
O(4)#1-Eu(1)-O(1) 152.3(3) O(3)#4-Eu(1)-O(2) 130.3(2)
O(5)#2-Eu(1)-O(1) 82.9(3) O(2)#5-Eu(1)-O(2) 76.8(2)
O(6)#3-Eu(1)-O(1) 86.5(3) O(1)-Eu(1)-O(2) 49.4(2)
O(3)#4-Eu(1)-O(1) 89.7(3) O(7)-Eu(1)-O(2) 112.4(3)
Complex 2
Tb(1)-O(4)#1 2.267(7) Tb(1)-O(1) 2.346(7)
Tb(1)-O(6)#2 2.292(8) Tb(1)-O(2)#5 2.355(6)
Tb(1)-O(5)#3 2.309(7) Tb(1)-O(7) 2.455(7)
Tb(1)-O(3)#4 2.320(8) Tb(1)-O(2) 2.822(7)
O(4)#1-Tb(1)-O(6)#2 86.0(3) O(1)-Tb(1)-O(2)#5 125.1(3)
O(4)#1-Tb(1)-O(5)#3 119.3(3) O(4)#1-Tb(1)-O(7) 76.4(3)
O(6)#2-Tb(1)-O(5)#3 133.5(3) O(6)#2-Tb(1)-O(7) 74.8(3)
O(4)#1-Tb(1)-O(3)#4 83.3(3) O(5)#3-Tb(1)-O(7) 144.8(3)
O(6)#2-Tb(1)-O(3)#4 149.4(3) O(3)#4-Tb(1)-O(7) 74.8(3)
O(5)#3-Tb(1)-O(3)#4 76.2(3) O(1)-Tb(1)-O(7) 77.6(3)
O(4)#1-Tb(1)-O(1) 154.1(3) O(2)#5-Tb(1)-O(7) 143.6(3)
O(6)#2-Tb(1)-O(1) 87.9(3) O(4)#1-Tb(1)-O(2) 146.3(2)
O(5)#3-Tb(1)-O(1) 82.5(3) O(6)#2-Tb(1)-O(2) 67.2(3)
O(3)#4-Tb(1)-O(1) 89.3(3) O(5)#3-Tb(1)-O(2) 72.2(2)
O(4)#1-Tb(1)-O(2)#5 78.1(3) O(3)#4-Tb(1)-O(2) 130.1(2)
O(6)#2-Tb(1)-O(2)#5 77.9(3) O(1)-Tb(1)-O(2) 49.4(2)
O(5)#3-Tb(1)-O(2)#5 71.2(3) O(2)#5-Tb(1)-O(2) 76.5(2)
O(3)#4-Tb(1)-O(2)#5 127.2(3) O(7)-Tb(1)-O(2) 113.4(2)
Symmetry transformations used to generate equivalent atoms for complex 1: #1 -x+7/4, y+1/2, -z+5/4; #2 -x+9/4, -y+7/4, z-1/2; #3
x-1/4, y+1/4, -z+3/2; #4 x+1/2, -y+7/4, -z+5/4 ; #5 -x+2, -y+2, -z+1. For complex 2: #1 -x+7/4, y+1/2, -z+5/4; #2 x-1/4, y+1/4,
-z+3/2; #3 x+1/2, -y+7/4, -z+5/4; #4 -x+9/4, -y+7/4, z-1/2; #5 -x+2, -y+2, -z+1.
Table S3. Saturated vapor pressure for each of the analytes at room temperature (25 °C).
Analytes Vapor Pressure
(in mmHg)
Reduction Potential
(in V vs SCE)
Nitrobenzene (NB)1 0.2416 −1.15
2-Nitrotoluene (2-NT)1 0.1602 −1.2
1,3-Dinitrobenzene(1,3-DNB)2 8.82 x 10-4 −0.9
1,4-Dinitrobenzene
(1,4-DNB)1 2.406 x 10-5 −0.7
2,4-dinitrotoluene (2,4-DNT)1 1.44 × 10-4 −1.0
2,6-dinitrotoluene
(2,6-DNT)1,3 5.61 × 10-4 −1.0
2,4,6-trinitrotoluene (TNT)1,4 8.02 × 10-6 −0.7
2,4,6-trinitrophenol (TNP)4 5.8 × 10-9 −0.63
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Inorg. Chem., 2009, 48, 7165.
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Table S4. Approximate sizes of the selected analytes.
Analytes Approximate Size (D×W×L, Å)
NB 3.4 × 6.2 × 8.6
2-NT 5.0 × 7.7 × 8.6
1,3-DNB 5.6 × 7.7 × 8.1
1,4-DNB 5.6 × 7.7 × 9.1
2,4-DNT 5.6 × 7.7 × 10.1
2,6-DNT 5.6 × 7.7 × 9.5
TNT 5.6 × 7.7 × 10.2
TNP 5.0 × 6.2 × 7.1
Table S5. HOMO and LUMO energies calculated for H3BTB and nitroaromatic explosives at
B3LYP/6-31G** level of theory.
Analytes HOMO (eV) LUMO (eV) Band gap
H3BTB -6.73074 -2.00385 4.72689
NB6 -7.5912 -2.4283 5.1629
2-NT5 -7.36454 -2.31722 5.04732
1,3-DNB6 -7.9855 -3.4311 4.5544
1,4-DNB5 -8.35250 -3.49679 4.85571
2,4-DNT6 -7.7645 -3.2174 4.5471
2,6-DNT6 -7.6448 -3.2877 4.3571
TNT6 -8.2374 -3.8978 4.3396
TNP6 -8.4592 -3.4926 4.9666
5 G. Y. Wang, C. Song, D. M. Kong, W. J. Ruan, Z. Chang and Y. Li, J. Mater. Chem. A., 2014, 2, 2213.
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